#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int cmp(const void* e1, const void* e2)
{
    return *(char*)e1 - *(char*)e2;
}
int longestPalindrome(char* s) {
    int numsSize = strlen(s);
    qsort(s, numsSize, sizeof(char), cmp);
    int result = 0;
    for (int i = 0; i < numsSize - 1; i++)
    {
        if (s[i] == s[i + 1])
        {
            result++;
            i++;
        }
    }
    if (numsSize == 1)
        return 1;
    else if (numsSize > 2 * result)
        return 2 * result + 1;
    else
        return 2 * result;
}

int main()
{
	return 0;
}